Collect and run healthchecks¶

Given you have healthchecks, there are two main ways to collect and run healthchecks:

run a shell command:
- using hospital.cli
- using nose [1]
perform GET requests to a web service: using hospital.wsgi.

If you want to setup another runner, notice that you can use the is_healthcheck() function to verify whether an object is a healthcheck or not.

hospital.cli¶

You can use hospital.cli to collect and run healthchecks:

$ python -m hospital.cli hospital.healthchecks.predictable
.
----------------------------------------------------------------------
Ran 1 test in 0.001s

OK

See python -m hospital.cli --help for detailed usage and options.

Nose¶

Here are guidelines to collect and run healthchecks with nose [1]. In the examples below, we run health checks of hospital project.

$ nosetests --all-modules --attr='is_healthcheck' hospital.healthchecks.predictable
.
----------------------------------------------------------------------
Ran 1 test in 0.001s

OK

Reciprocally, you may want to skip healthchecks when you run tests. With nose, it could be:

$ nosetests --all-modules --attr='!is_healthcheck' hospital.healthchecks

----------------------------------------------------------------------
Ran 0 tests in 0.000s

OK

Tip

–all-modules option [2] makes Nose collect tests in all modules. Without the option, it would have collected modules or packages named “tests”, and not “healthchecks”.

hospital.wsgi¶

You can use hospital.wsgi to expose healthchecks over HTTP:

$ python -m hospital.wsgi hospital.healthchecks.predictable
Serving on 0.0.0.0 port 1515...

See python -m hospital.wsgi --help for detailed usage and options.

Then each time you perform a GET on the server’s root, healthchecks are collected and run.

The status code of the response is 200 in case all healthchecks passed, else it is 500.

$ curl -X GET -I http://localhost:112112/
HTTP/1.0 200 OK
Date: Fri, 28 Feb 2014 13:19:08 GMT
Server: WSGIServer/0.1 Python/2.7.5+
Content-Type: application/json; charset=utf-8
Content-Length: 520

The output is JSON:

{
    "status": "pass",
    "details": [
        {
            "test": "Health checks are collected.",
            "status": "pass"
        }
    ],
    "summary": {
        "skip": 0,
        "pass": 1,
        "expected_failure": 0,
        "error": 0,
        "fail": 0,
        "total": 1,
        "unexpected_success": 0
    }
}

Notes & references

[1]	(1, 2) https://nose.readthedocs.org/

[2]	http://nose.readthedocs.org/en/latest/usage.html#cmdoption–all-modules